tell the sizing from the picture but I think it's definitely white glass subway tile. I would say it could be 3x6 http://www.subwaytileoutlet.com/products/White-Glass-Subway-Tile.html
or 4x12: http://www.subwaytileoutlet.com/products/White-Glass-4x12-Subway-Tile
A sample would give you a better idea of
which size you like better. Best of luck! If you have any questions about your back splash project, we would be happy to help.